In modern consumer electronics, portable computing appliances such as, for example, laptops, notebooks, tablet computers, smart phones and portable timepieces lack sufficient space to house relatively large devices (e.g., microphones, speakers, accelerometers, barometric and other ambient pressure sensors, memory, processing units, or the like). Thus, the sizes of devices used in such appliances are becoming more and more compact and decreasing in size. The various devices, however, perform different functions (e.g., sound pick-up, pressure sensing, etc.), and more than one signal conditioning unit or circuit must typically be incorporated into an appliance for processing of the different signals. Therefore, a number of different devices (e.g., transducers, sensors and/or processing units) must typically be incorporated into portable computing appliances, leading to product space and integration challenges that are not solved merely by reducing the sizes of each of these components individually.
Moreover, many portable computing and communication appliances are used in a variety of environments and under a variety of environmental conditions. Such conditions may include, for example, wind or rain, noisy crowds or other environments with background noise. Further, many portable computing and communication appliances are used in dynamic situations and may transition from one environment to another environment during a period of use. Under those conditions, an appliance's ability to observe a given audio source may be impaired. For example, a microphone port in the appliance can become partially or wholly occluded by a user's hand or rain. Scratching or handling of the appliance, or wind blowing across or into the microphone port, can induce pressure fluctuations around a microphone's acoustically sensitive region and impair (or even obscure) observations of an intended audio source. Moreover, such conditions can cause a microphone clipping. Such acoustic challenges are not solved merely by avoiding such uses or conditions.